1. Field of the Invention
The present invention relates to vehicle body closure panels, in which a torque rod with end assemblies forms a counterbalanced pivot connection between a tailgate and vehicle body pillars, the counterbalance biasing the torque rod to an unbiased tailgate position permitting tailgate removal from the vehicle body.
2. Background Art
Vehicle body closure members such as a tailgate are pivotally mounted between body side panels forming the pillars at the rear of the vehicle. The tailgate pivots about a hinge axis between a horizontal, open position and a vertical, closed position. Preferably, the mounting assemblies for the tailgate permit the tailgate to be removed, and this has been accomplished in a known construction when the tailgate is pivoted to a position between the fully open or fully closed position. For example, the tailgate may include hinge pins that extend outwardly along the hinge axis that removably connect into brackets carried on the truck body. When the tailgate is pivoted to a predetermined intermediate position, for example, 15xc2x0 away from the fully closed position, at least one of the hinge pins slips through a slot in the connecting bracket as the tailgate is lifted at one end from the truck body.
Some of the tailgate mounting assemblies include a spring bias assist for assisting movement and counterbalancing the weight of a tailgate during opening and closing movements. One previously known mechanism in which a torque rod provides spring biasing between the tailgate and the body panel pillars carries the torque road on assemblies that form the pivots for the tailgate. Since the torque rod forms a portion of the pivot assembly, the torque rod must be installed for the tailgate to pivot and thus complicates the assembly procedure. Moreover, the torque rod may require particularly configured ends that complicate production of the parts before assembly.
A previously known tailgate may use hinge pin trunnions for pivoting and the torque rod is preformed and installed into the tailgate in a complex and intricate procedure. For example, during assembly of the tailgate, the stationary end of the rod has to be aligned with an aperture that exposes the end for attachment outside of the tailgate while the anchoring end is aligned with a reenforcement plate located inside the tailgate. All of the aligning must be performed while the torque rod is carried within the interior of the tailgate and the procedure may be difficult and time consuming. Moreover, numerous components are required to assemble the torque rod to the tailgate. Other types of springs used in place of the torque rod are difficult to install within the confines of tailgates made of inner and outer panels joined together before the hinge assembly is mounted. Moreover, such assemblies may be difficult to repair and replacement parts are complex and expensive.
The present invention overcomes the above mentioned disadvantages by providing a tailgate counterbalancing hinge in a vehicle closure assembly that includes a torque rod having first and second end assemblies, at least one end assembly being readily attachable to and removable from the torque rod. The first end assembly includes a first support for pivotally carrying the tailgate adjacent a body pillar. The first support preferably includes a cup, and a retainer bushing pivotally received by said cup includes a stem for locking said bushing with respect to the tailgate. The second end assembly has a second support for pivotally carrying a tailgate adjacent to a body pillar. The second support preferably has a key. In the preferred embodiment, a spriget combines the key with a mount for securing the key to a facing body panel, preferably a body pillar. A pivot body has a slot aligned for reception of the key. A pivot bushing is received in an opening in said tailgate and carries the pivot body. The torque rod has a first end securely received in the first end assembly for movement with the retainer bushing, and a second end securely received in the second end assembly by the pivot body.
In the preferred embodiment, the torque rod has a faceted crosssection at least at an end, and preferably at each end. As used in the present application, the faceted cross-section refers to any cross-section having at least one surface discontinuity that prevents rotation within a correspondingly shaped, compatible piece. The cross-section may be longitudinally continuous for ease of manufacture of the torque rod or may be formed only on parts of the rod.
In addition, the present invention comprises a method for assembling a selectively removable tailgate to a vehicle body pillar at each end of the tailgate, wherein the hinge includes a torque rod with a faceted cross-section or at least end portions with a faceted cross-section. The method includes receiving a first end of the torque rod in a retainer bushing with a faceted cross-section receiver. The method also includes receiving a second end of the torque rod in a cup with a faceted cross-section receiver, retaining the retainer bushing with respect to the tailgate, and retaining the cup by slidably receiving the cup with respect to a spriget fixed to a body pillar. By sliding the retainer bushing over a spriget""s key, fixed to the vehicle body pillar, the pillar pivotally supports a retainer bushing.